[feature]: Add the possibility to pay a blinded path when the sender is also the introduction point.

[ziggie1984]

I think it makes sense to also allow the introduction point of a blinded path pay the invoice.

[saubyk]

It might be a good idea to articulate specific benefits of this scenario, before initiating any dev work here.

If my understanding of route blinding is correct, when the introduction point is also the payer of the invoice then it knows the entire route as well. So there is no privacy benefit for the receiver really.

What possible use cases can benefit from enabling this?

[ellemouton]

If my understanding of route blinding is correct, when the introduction point is also the payer of the invoice then it knows the entire route as well.

No that is incorrect. It just would know the next hop

What possible use cases can benefit from enabling this?

So that a node is able to pay an invoice even if it happens to be the chosen intro node

[carlaKC]

I think it makes sense to also allow the introduction point of a blinded path pay the invoice.

Definitely does! Was excluded from original PRs to keep the scope down.

[AndySchroder]

Wondering, can the allow-circular-route option allow any hacks to make this work by adding some extra hops in and then routing back through yourself later? For example, it is a hacky way to workaround #7419 (which is a mildly related bug).